Factors associated with progression of diabetic retinopathy, a multi-centric study in Kuwait

Diabetic retinopathy [DR] is a progressive sight threatening diabetic complication. The prognosis seems to be related to largely modifiable risk factors. The aim of the study was to identify factors that could be associated with progression of DR. among adult diabetic patients attending primary health care centers in Kuwait. The current study is a part of a larger multi-centric one that included 704 diabetic patients. A nested case-control study was used whereas all patients with proliferative diabetic retinopathy [PDR] [case group, n = 33] were compared with all other diabetic patients with non-proliferative diabetic retinopathy [NPDR] [control group, n = 183] to determine the associated factors with cases. A pre-designed questionnaire included socio-demographic, clinical data, laboratory investigations, in addition to health care characteristics and personal practice. Basically univariate analyses were followed by multiple logistic regression analysis. Out of 704 diabetic patients participated in the study 216 were diagnosed as having DR with an overall 30.7% prevalence rate. Among 216 patients with DR, 33 were diagnosed as PDR [4.7%] and 183 were diagnosed as NPDR [26.0%]. Of the personal factors examined, nationality was the only significant determinant of PDR [OR = 0.8, 95% CI: 0.71 - 0.9]. Among clinical factors, patients with type 2 - insulin treated diabetes were more prone to have PDR as compared to type 1 [OR = 1.2, 95% CI: 1.1 - 1.4]. Duration of diabetes > 20 years was a significant predictor of PDR [OR = 1.3, 95% CI: 1.1 - 1.5]. Also, poor hyperglycemia and hypertension were significantly modifiable risk factors [OR = 1.2, 95% CI: 1.1 - 1.3] and [OR = 1.2, 95% CI: 1.1 - 1.4] respectively. Ex-smoking was significantly associated with PDR [OR = 8.3, 95% CI: 3.3 - 23.8]. Hyperglycemia and hypertension are the strongest modifiable risk factor for PDR. Patients with longer duration of diabetes particularly those with type 2-insulin treated diabetes were more prone for PDR and should be regularly screened for DR